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Related Manuals for Marti Electronics STL-10A
Summary of Contents for Marti Electronics STL-10A
- Page 1 MARTI ELECTRONICS STL TRANSMITTER MODEL STL–10A October, 2001 597–9500...
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Page 2: Table Of Contents
CONTROL BOARD 800–197 AUDIO BOARD 800–194 MODULATOR 800–195 MULTIPLIER BOARD 800–163 RF POWER AMPLIFIER 800–374B AND 800–373B DUAL LINK STEREO STL TEST EQUIPMENT TOOLS FOR ALIGNMENT OF STL–10A SERIES TRANSMITTERS Marti Electronics 2000 ALL RIGHTS RESERVED Printed in the U.S.A. - Page 3 TUNE–UP PROCEDURE FOR STL–10A MODULATOR CIRCUIT BOARD 800–195 ADJUSTMENTS STL–10A TRANSMITTER TEST REPORT AUDIO CIRCUIT BOARD 800–194 ADJUSTMENTS MULTIPLIER CIRCUIT BOARD 800–163 ADJUSTMENTS RF POWER AMPLIFIER BOARD 800–374B AND 800–373B ADJUSTMENTS POWER CONTROL POT CALIBRATION B+ ADJUST FORWARD POWER METER ADJUST REVERSE POWER METER ADJUST PA CURRENT ADJUST FREQUENCY MEASUREMENT...
- Page 4 Marti Electronics. has been altered, improperly handled, or damaged in any way. Marti Electronics may make improvements and/or The Seller is in no event liable for consequential dam- changes in this manual or in the product described here- ages, installation cost or other costs of any nature as a in at any time.
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Page 5: Introduction - Stl-10A
INTRODUCTION – STL–10A. The MARTI STL–10A Studio Transmitter Link/Inter–city Relay is a line–of–sight FM communications system pro- viding a high quality broadcast audio channel with two optional sub–channels. A dual link for stereo provides two identical broadcast quality channels with better than 70 dB stereo cross–talk and four optional sub–channels. These systems offer greater rejection of interference, superior noise performance, much lower channel cross–talk, and greater redundancy than currently available composite STL systems. -
Page 6: Stereo Stl System Block Diagram - 702-058
FIGURE 2. STEREO STL SYSTEM BLOCK DIAGRAM – 702–058... -
Page 7: Specifications
Automatic output power control. The power control maintains the output power to a specific level and is independent of temperature and voltage changes. Twelve segment bar graph for display of peak transmitter modulation. The five highest LED’s (100% to 250%) have a “peak–hold” feature which will display instantaneous peak value for one second, a valuable feature when dealing with pre–emphasized program audio. - Page 8 TABLE 1. STL–10A ELECTRICAL AND PHYSICAL SPECIFICATIONS (Sheet 1 of 2) PARAMETER SPECIFICATION ELECTRICAL FREQUENCY BAND 850 MHz to 960 MHz as specified. MAXIMUM POWER OUTPUT 10 watts, 0.5 watts,850 to 960 MHz. OUTPUT CONNECTOR UG–58 (Type N Female) OUTPUT IMPEDANCE 50 Ohms MODULATION Direct FM...
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Page 9: Unpacking And Inspecting
TABLE 1. STL–10A ELECTRICAL AND PHYSICAL SPECIFICATIONS (Sheet 2 of 2) PARAMETER SPECIFICATION ENVIRONMENTAL OPERATING TEMPERATURE –20 C to +50 C (–4 F to +122 F). RANGE * Voltage must be specified with order. ** Requires APS–28/18 Power Supply UNPACKING AND INSPECTING. This equipment was factory tested, inspected, packed, and delivered to the carrier with utmost care. -
Page 10: Antenna Installation
The following suggestions are offered to help those responsible for antenna installations avoid costly errors in as- sembly and adjustment. Marti Electronics Inc. assumes no responsibility for the installation and performance of antenna systems associated with the equipment. The following text presents a listing of some of the most frequently asked questions associated with the equipment. -
Page 11: Location And Grounding Of Coaxial Cable
Location and Grounding of Coaxial Cable. Keep the STL receiver coaxial cable as far from the broadcast transmitter and coaxial cable as possible. DO NOT STRAP RECEIVER CABLE TO THE MAIN ANTENNA CABLE AT ANY POINT. PLACE THE RECEIVER ANTENNA COAXIAL CABLE ON THE OPPOSITE SIDE OF THE TOWER FROM THE MAIN ANTENNA CABLE. -
Page 12: Forward-Reflected Switch And Rf Power Meter
FORWARD–REFLECTED Switch & RF Power Meter. The RF POWER METER, with its selector switch, allows monitoring parameters within the transmitter as follows: 1. When switched to “FORWARD POWER”, the meter indicates the RF power output of the STL–10A transmitter. The maximum power is 10 Watts for the 850–960 MHz band (United States). 2. -
Page 13: Pre-Emphasis Switches
PRE–EMPHASIS SWITCHES. Two programmable switches S1 and S2 on audio board 800–194 enable the user to select flat, 25, 50, or 75 micro–second pre–emphasis characteristics. The selection of one of these options in the transmitter requires a corresponding selection of S1 and S2 on receiver audio board 800–205. Refer to STL–10A adjustment location dia- gram at the end of this manual for the location of these switches. -
Page 14: Noise
NOISE. Noise measurements should be made first, since high noise levels will influence distortion readings. Also ground loops in the audio oscillator to transmitter connections and distortion analyzer to receiver connections must be resolved before testing begins. The influence of high RF fields upon the test equipment must be determined and corrected before accurate measurements can be made. -
Page 15: Audio Board 800-194
AUDIO BOARD 800–194. The 600 ohm balanced audio input to the transmitter is connected to the inputs of unity gain differential amplifier IC–1A. Potentiometer R9 is provided for adjusting the amplifier to produce the maximum common mode rejection (CMR). The output of the differential amplifier is directly coupled to the pre–emphasis amplifier. The negative feedback circuit of this amplifier has two capacitors selected by switches S1 and S2 which provides options of 0, 25, 50, or 75 microsecond pre–emphasis. -
Page 16: Fcc Emission Profile (500 Khz Channel) Drawing
FIGURE 3. FCC EMISSION PROFILE (500 KHZ CHANNEL) DRAWING... -
Page 17: Fcc Emission Profile (200 Khz Channel) Drawing
FIGURE 4. FCC EMISSION PROFILE (200 KHZ CHANNEL) DRAWING... -
Page 18: Test Equipment
TEST EQUIPMENT. The following text presents the test equipment required for alignment of STL–10A Transmitters. A sample test re- port is also provided in the following text. 1. Bird, Model #43, Wattmeter, 50 ohm impedance. 2. Bird, 25–Watt Element, 400–1000 MHz. 3. -
Page 19: Stl-10A Transmitter Test Report
STL–10A TRANSMITTER TEST REPORT CUSTOMER: _________________________________________________________________________ ADDRESS: ___________________________________________________________________________ FREQUENCY: ______________________________ Serial #: ______________________________ Modulator Bias: __________________ 100% Modulation __________________________ +kHz. Total DC Current __________________________ amperes TEST POINT READINGS TP 1 __________ 0.15 V dc – 0.60 V dc TP 2 __________ 0.70 V dc –... -
Page 20: Audio Circuit Board 800-194 Adjustments
AUDIO CIRCUIT BOARD 800–194 ADJUSTMENTS. 1. Connect an audio voltmeter to Pin 1 (modulator audio) of audio circuit board 800–194. Connect a jumper between terminal 1 and 2 (the outer terminals) of TB–1 (the 600 ohm balanced input). Connect an audio signal generator between chassis and either Terminal 1 or 2.